Problem: What is the slope of the line that passes through $(2,3)$ and $(4,2)$? Express your answer as a common fraction.
Solution: The slope of the line is equal to the change in $y$ divided by the change in $x$. That is, the slope of the line is $\frac{2-3}{4-2}=\frac{-1}{2}=\boxed{-\frac{1}{2}}$.